02-10-2010 - Breastfeeding moms....

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Breastfeeding and Fertility

By Kelly Bonyata, BS, IBCLC

• How can I use breastfeeding to prevent pregnancy?
• The transition to full fertility
• Do I need to wean to get pregnant?
• References and Additional Resources
• Fertility and conceiving while breastfeeding
• Exclusive breastfeeding/Lactational Amenorrhea Method of birth control
• Print Resources

How can I use breastfeeding to prevent pregnancy?

The Exclusive Breastfeeding method of birth control is also called the Lactational Amenorrhea Method of birth control, or LAM. Lactational amenorrhea refers to the natural postpartum infertility that occurs when a woman is not menstruating due to breastfeeding. Many mothers receive conflicting information on the subject of breastfeeding and fertility.

Myth #1 – Breastfeeding cannot be relied upon to prevent pregnancy.

Myth #2 – Any amount of breastfeeding will prevent pregnancy, regardless of the frequency of breastfeeding or whether mom’s period has returned.

Exclusive breastfeeding has in fact been shown to be an excellent form of birth control, but there are certain criteria that must be met for breastfeeding to be used effectively.

Exclusive breastfeeding (by itself) is 98-99.5% effective in preventing pregnancy as long as all of the following conditions are met:

1. Your baby is less than six months old
2. Your menstrual periods have not yet returned
3. Baby is breastfeeding on cue (both day & night), and gets nothing but breastmilk or only token amounts of other foods.

Effectiveness of Birth Control Methods Number of Pregnancies per 100 Women
Method	Perfect Use	Typical Use
LAM	0.5	2.0
Mirena® IUD	0.1	0.1
Depo-Provera®	0.3	3.0
The Pill / POPs	0.3	8.0
Male condom	2.0	15.0
Diaphragm	6.0	16.0
* Adapted from information at plannedparenthood.org. See comparison of effectiveness for birth control methods for more information.

How can I maximize my natural period of infertility?

Timing for the return to fertility varies greatly from woman to woman and depends upon baby's nursing pattern and how sensitive mom's body is to the hormones involved in lactation.

• Breastfeeding frequency and total amount of time spent breastfeeding per 24 hours are the strongest factors leading to the return of fertility: a mother is more likely to see the return of fertility if baby's nursing frequency and/or duration is reduced, particularly if the change is abrupt.
• In some populations, research has shown that night nursing slows the return to fertility.
• One study showed that mothers who were separated from their infants (but expressed milk to provide 100% breastmilk for baby) had a higher pregnancy risk (5.2%) during the first 6 months (Valdes 2000).
• The introduction of solid food can also be a factor in the return of fertility. Once baby starts solids (if mom's cycles have not returned), the natural period of infertility may be prolonged by breastfeeding before offering solids, starting solids gradually, and not restricting nursing.

You can achieve higher effectiveness by practicing ecological breastfeeding:

• keeping baby close
• breastfeeding on cue (day and night)
• using breastfeeding to comfort your baby
• breastfeeding in a lying-down position for naps and at night
• using no bottles or pacifiers

If you practice ecological breastfeeding:

• Chance of pregnancy is practically zero during the first three months, less than 2% between 3 and 6 months, and about 6% after 6 months (assuming mom's menstrual periods have not yet returned).
• The average time for the return of menstrual periods is 14.6 months.
• Moms whose cycles return early tend to be infertile for the first few cycles. Moms whose cycles return later are more likely to ovulate before their first period.
  Source: Natural Child Spacing and Breastfeeding by Jen O'Quinn

Source: Natural Child Spacing and Breastfeeding by Jen O'Quinn

While it is possible for a nursing mom to become pregnant while she is breastfeeding and before she has her first menstrual period, it is rare. Most moms do not get pregnant until after their first period (often referred to as the "warning period"). Even after that, while some can become pregnant the first cycle, others will require months of cycles before pregnancy can occur. Still others (this is quite uncommon) may not be able to become pregnant until complete weaning has occurred.

The transition to full fertility

Several studies have indicated that fertility and ovarian activity return step by step (Ellison 1996, p. 326-327):

1. Follicular activity without ovulation (No chance of pregnancy.)
   1a. Menstruation without ovulation (This does not always occur--see below.)
2. Ovulation without luteal competence (After the egg is released, fertilization may take place. During the luteal phase, the uterine lining is prepared for implantation as the egg travels down the fallopian tube and into the uterus. If the uterine lining is not adequately prepared for implantation, the implantation will probably not be successful.)
3. Full luteal competence (Full fertility -- at this point breastfeeding no longer has any effect on your chance of pregnancy.)

It is possible to have one or (occasionally) more periods before you start ovulating. In this case, menstruation begins during the first stage of the return to fertility --before ovulation returns. Cycles without ovulation are most common during the first six months postpartum. For other mothers, the first menstruation is preceded by ovulation - a longer period of lactational amenorrhea increases the likelihood that you will ovulate before that first period.

A very small percentage of women will become pregnant during their first postpartum ovulation, without having had a postpartum period. Per fertility researcher Alan S. McNeilly, this "is rare and in our experience is related to a rapid reduction in suckling input."

It is not uncommon for breastfeeding mothers to report cyclical cramping or PMS-type symptoms - symptoms of an oncoming period without the period - for weeks or even months before their period returns. When this happens, the body is probably "gearing up" for the return of menstruation, but breastfeeding is still delaying the return of fertility.

The amount of time that it takes for the transition to full fertility varies from woman to woman. In general, the earlier that your menses return, the more gradual the return to full fertility.

Do I need to wean to get pregnant?

Probably not. If you are still transitioning to full fertility (as discussed above), breastfeeding may affect the success of implantation. Once implantation is successful, breastfeeding should not affect a healthy pregnancy (see A New Look at the Safety of Breastfeeding During Pregnancy for more information). If your periods have come back and settled into a regular pattern, it is likely that breastfeeding is no longer affecting your fertility.

Many moms can conceive without deliberately changing their toddler's nursing patterns. There is no "magic" threshold of breastfeeding that will allow you to conceive -- every mother is different. Some moms need to stretch out nursing frequency and/or shorten nursing sessions to make it easier to conceive -- babies naturally do this themselves as they get older, so one of your options is simply to wait a bit.

Changes that are more abrupt tend to bring fertility back faster (e.g., cutting out one nursing session abruptly, rather than gradually decreasing nursing time at that session) --even if you continue to breastfeed a great deal-- this is why many mothers experience the return of fertility when their child sleeps through the night or starts solid foods. If you decide to make changes to your nursing pattern, the time of day that you make the change (e.g., cutting out or shortening a nighttime nursing session as opposed to a daytime nursing session) should not make that much of a difference. Current research indicates that nursing frequency and total amount of time at the breast per 24 hours are the most important factors, rather than the time of day that the suckling occurs.

A few moms do find it impossible to conceive while nursing, but this is not at all common.

Many mothers wonder whether breastfeeding will affect the reliability of pregnancy tests. It does not -- pregnancy tests measure the amount of the hormone hCG (human chorionic gonadotropin) in blood or urine, and hCG levels are not affected by breastfeeding. The developing placenta begins releasing hCG upon implantation; a pregnancy can generally be detected with a pregnancy test within 7-14 days after implantation.

For more information, see Getting Pregnant While Breastfeeding by Hilary Flower.

When you do get pregnant while breastfeeding, what next? See Nursing During Pregnancy & Tandem Nursing for more information.